It looks like T-Mobile and AT&T aren’t the only companies issuing mid-September blackout dates for employees. According to an alleged internal company document leaked to AppleInsider, Apple has issued a vacation blackout period for Apple Care employees from September 15-28. If this is true, it is just further evidence pointing to the highly rumored September 20 launch date for the iPhone 5S and the iPhone 5C.

Whereas T-Mobile’s purported blackout period is only for the first weekend the new iPhones are expected to go on sale, Apple Care employees also must deal with the launch of iOS 7, so the longer blackout period makes sense.

In the past, iPhones have typically been made available around a week and a half after the announcement. Apple is expected to announce the iPhone 5S and the lower-priced iPhone 5C at an event on September 10, so a September 20 availability date looks likely.